All content should be available on all servers and there are no exceptions.
The only thing that has been removed from the subscription servers is the shit that makes people want to go play there instead of playing on the free one.
I think the fatalities should be available on the subscription, possibly without the stats buff. Combat mounts and stuff like that - no. It will create the unbalance that drives people away from the free2play. The problem isn't that the spinner is cash shop mount. The problem is that not everyone can have it, which creates the imbalance. All costumes and all vanity should be available on the subscription, including ship hulls and itemshop ship accessories (zem, elven set) as vanities.
This suggestion if implemented as the OP suggested would be the death of the game in every way possible. It's one of the worst, most selfish suggestions anyone has ever made for Allods Online.
Considering I know how much some people spend on Allods f2p, I'll estimate that every active player on the f2p server is about $30 a month. It's an extremely rough estimation. Many do not spend anything, but many spend over $50 a month, and enough go a lot higher than that $50. Your suggestion cannot be "the f2p should suck it, and the p2p should pay $5 for uber advantage". If you want such big advantage (artificially slowing down updates on the f2p to benefit YOU is that), you should consider paying more than mere $5. I have a better suggestion than yours - make the subscription server free, don't change it at all and release updates in advance there. That will surely make it lively. Allods' only strength is that nobody has to pay for content access. There is no content exclusive to those that pay. This is vital in an MMO like this, and it is why so many other f2p mmos are unplayable for me.
If half the people on the p2p talked one player into joining, that would increase your population by 50%. And right now, access is free. Now is the time to do it. Stop being lazy! I have 4 friends I talked into joining the f2p. Everyone can do it. Jesus!